"Greinke is a fine prospect no doubt, after all, he was only 20, and he outperformed Bonderman at the same age, and people were still optimistic about him after 2003.

However, the hype surrounding Greinke is far beyond that. The comps that people are giving for Greinke are guys like Maddux, Saberhagen, and now Schilling. Perhaps we're being a bit over optimistic here?

Yes, he has superhuman control, but that's exactly the problem. If his overall periphs are so mediocre despite the fabulous control, then he's got less room to grow, since K rate generally declines, and his BB rate is already essentially maxed out. (I won't common on HR rate, since that's inherently flukish.)

This is like the old adage about the two runners who run the 100 meter dash equally fast. One has perfect form, the other has horrible form. Which do you want? The guy with horrible form, because if you can fix that, then he'll be even better.

Greinke, in the stat that's most likely to improve, simply doesn't have much further to go, and realistically probably can't get any better.

In the stat that's most likely to decline however, he's already starting out below league average, and if he declines in a fashion similar to that of most pitchers, then he'll be out of baseball sooner than you think.

Yes, Greinke is starting out with old-pitcher skills, and yes, that's a big problem."

I wish I had said it as well.

I'm a bit less negative, however, and would simply reiterate that, being 20, Greinke may indeed pick up velocity and movement on some of his pitches. I'm cautiously optimistic. A couple of commenters also noted that despite his famed control his vulnerability to the homerun may be related to trying to throw his 87 mph fastball a little too finely. In other words, he may have considerable room to grow in learning his craft as well. Both of which project to a higher upside.